<!-- 钩子函数 页面挂载 -->

<script src="vue.js"></script>

<div id="app"> 
    <p>{{msg}}</p> 
</div>

<script>
 var vue=new Vue({ 
     el: '#app', 
     data:{ 
         msg:"我有回来了" 
     },
     mounted(){ 
          console.log("页面挂载之后") 
          console.log(this.$el.innerHTML) 
     }, 
     beforeMount(){ 
         console.log("页面挂载之前") 
         console.log(this.$el.innerHTML) 
     }
    })
 </script>